Coloured soda-lime glass

ABSTRACT

The present invention relates a coloured soda-lime glass which comprises iron in a quantity which, expressed in weight of the oxide Fe2O3 in relation to the total weight of glass, is greater than or equal to 0.5, and less than or equal to 1.0% (quantity of total iron), a ratio of Fe2+/total Fe (redox ratio) in the range of between 20 and 65% and titanium in a quantity which, expressed in weight of TiO2 in relation to the total weight of glass, is greater than or equal to 1.0%. This glass has a light transmission (TLA4) in the range of between 15 and 55%, a total transmission in the ultraviolet (TUV4) of less than or equal to 30%, and a dominant wavelength in transmission (λD) of less than or equal to 491 nm. This glass can be used, for example, as side glazing, rear-view window, roof glazing or opening roof of a motor vehicle.

The present invention relates to a coloured soda-lime.

Soda-lime glass can be clear or coloured, for example, green, grey orblue in transmission.

The expression “soda-lime glass” is used here in the wide sense andrelates to any glass which is likely to contain the following principalglass-forming constituents (in percentages by weight): SiO₂ 60 to 75% Na₂O 10 to 20%  CaO 0 to 16% K₂O 0 to 10% MgO 0 to 10% Al₂O₃ 0 to 5% BaO 0 to 2%  BaO + CaO + MgO 10 to 20%  K₂O + Na₂O  10 to 20%.  B₂O₃ 0to 5% 

In some cases, soda-lime glass can have a total percentage by weight ofBaO, CaO and MgO greater than 10%, and even greater than 12%.

This type of glass is very widely used in the field of glazing forautomobiles or buildings, for example. It is usually manufactured in theform of a ribbon by the float process. Such a ribbon can be cut intosheets which can then be bent or can undergo treatment to improve theirmechanical properties, e.g. a thermal toughening step.

It is generally necessary to relate the optical properties of a glasssheet to a standard illuminant. In the present description, two standardilluminants are used: illuminant C and illuminant A defined by theCommission Internationale de l'Eclairage (C.I.E.). Illuminant Crepresents average daylight having a colour temperature of 6700 K. Thisilluminant is especially useful for evaluating the optical properties ofglazing intended for buildings. Illuminant A represents the radiation ofa Planck radiator with a temperature of about 2856 K. This illuminantdescribes the light emitted by car headlights and is essentiallyintended to evaluate the optical properties of glazings intended forautomobiles.

The Commission Internationale de l'Eclairage has also published adocument entitled “Colorimétrie, Recommandations Officielles de laC.I.E. [Colorimetry and Official Recommendations of the C.I.E.]” (May1970) which describes a theory in which the calorimetric coordinates forlight of each wavelength of the visible spectrum are defined so thatthey can be represented on a diagram having orthogonal axes x and y,called the C.I.E. trichromaticity plot 1931. This trichromaticity plotshows the locus representative of light of each wavelength (expressed innanometers) of the visible spectrum. This locus is called the “spectrumlocus” and light having coordinates lying on this spectrum locus is saidto have 100% excitation purity for the appropriate wavelength. Thespectrum locus is closed by a line called the purple boundary whichconnects the points of the spectrum locus, the coordinates of whichcorrespond to wavelengths of 380 nm (violet) and 780 nm (red). The arealying between the spectrum locus and the purple boundary is thatavailable for the trichromaticity coordinates of any visible light. Thecoordinates of the light emitted by illuminant C, for example,correspond to x=0.3101 and y=0.3162. This point C is regarded asrepresenting white light, and consequently has an excitation purityequal to zero for any wavelength. Lines may be drawn from point C to thespectrum locus at any desired wavelength and any point lying on theselines may be defined not only by its x and y coordinates, but also as afunction of the wavelength corresponding to the line on which it liesand of its distance from point C relative to the total length of thewavelength line. Consequently, the colour of the light transmitted by acoloured glass sheet may be described by its dominant wavelength (λD)and its excitation purity (P) expressed as a percentage.

The C.I.E. coordinates of light transmitted by a coloured glass sheetwill depend not only on the composition of the glass but also on itsthickness. In the present description, as in the claims, all the valuesof the excitation purity P and the dominant wavelength λ_(D) of thetransmitted light are calculated from the spectral specific internaltransmissions (SIT_(λ)) of a glass sheet 5 mm in thickness withilluminant C from a solid viewing angle of 2°. The spectral specificinternal transmission of a glass sheet is governed solely by theabsorption of the glass and can be expressed by the Beer-Lambert law:SIT _(λ) =e ^(−E.A) ^(λ)

-   -   where A_(λ) is the absorption coefficient (in cm⁻¹) of the glass        at the wavelength in question and E the thickness (in cm) of the        glass. In a first approximation, SIT_(λ) may also be represented        by the formula:        (I₃ +R ₂)/(I ₁ −R ₁)        where I₁ is the intensity of the incident visible light on a        first face of the glass sheet, R₁ is the intensity of the        visible light reflected by this face, I₃ is the intensity of the        visible light transmitted from the second face of the glass        sheet and R₂ is the intensity of the visible light reflected by        this second face towards the interior of the sheet.

The following are also used in the following description and the claims:

-   -   for illuminant A, the total light transmission (TLA) measured        for a thickness of 4 mm (TLA4) from a solid viewing angle of 2°.        This total transmission is the result of the integration between        the 380 and 780 nm wavelengths of the expression: Σ        T_(λ).E_(λ).S_(λ)/Σ E_(λ).S_(λ) in which T_(λ) is the        transmission at wavelength A, E_(λ) is the spectral distribution        of illuminant A and S_(λ) is the sensitivity of the normal human        eye as a function of wavelength λ;    -   the total energy transmission (TE) measured for a thickness of 4        mm (TE4). This total transmission is the result of the        integration between the 300 and 2500 nm wavelengths of the        expression: Σ T_(λ).E_(λ)/ΣE_(λ). The energy distribution E_(λ)        is the spectral energy distribution of the sun at 30° above the        horizon with an air mass equal to 2 and an inclination of the        glazing of 60° relative to the horizontal. This distribution,        called “Moon distribution”, is defined in the standard ISO 9050;    -   the selectivity (SE) measured as the ratio of the total light        transmission for illuminant A to the total energy transmission        (TLA/TE);    -   the total transmission in the ultraviolet, measured for a        thickness of 4 mm (TUV4). This total transmission is the result        of the integration between 280 and 380 nm of the expression: Σ        T_(λ).U_(λ)/Σ U_(λ) in which U_(λ) is the spectral distribution        of the ultraviolet radiation that has passed through the        atmosphere, defined in the standard DIN 67507;    -   the Fe²⁺/total Fe ratio, sometimes called the redox ratio, which        represents the value of the ratio of weight of atoms of Fe⁺² to        the total weight of iron atoms present in the glass and is        obtained by the formula:        Fe²⁺/total Fe=[24.4495×log(92/τ₁₀₅₀)]/τ_(Fe2O3)    -   where τ₁₀₅₀ represents the specific internal transmission of the        5 mm thick glass at the 1050 nm wavelength, t_(Fe2O3) represents        the total iron content expressed in the form of oxide Fe₂O₃ and        measured by X-ray fluorescence.

Coloured glass can be used in architectural applications and as glazingfor railway carriages and motor vehicles. In architectural applications,glass sheets 4 to 6 m in thickness are generally used, while in theautomotive field thicknesses of 1 to 5 mm are normally employed,particularly for the production of monolithic glazing, and thicknessesof between 1 and 3 mm in the case of laminated glazing, especially forwindscreens, two glass sheets of this thickness then being bondedtogether by means of an interlayer film, generally made of polyvinylbutyral (PVB).

One of the objects of the invention is to provide a soda-lime glass oflow light transmission, preferably blue in colour, which enables theunpleasing discolouration of the objects located inside areas enclosedby this glass to be restricted.

The European patent application EP 0 101 36 20 A1 and the internationalapplication PCT/EP01/06861 describe highly selective glasses containingiron with a high redox ratio (Fe²⁺/total iron), and also cobalt and/orchromium and/or vanadium respectively. However, to promote a high redoxratio may be detrimental to other optical properties such as totaltransmission in the ultraviolet which is responsible for thediscolouration of objects located inside areas enclosed by such glasses.

The invention proposes glass compositions which have all the desiredproperties and in particular that of a filter for ultraviolet solarradiation.

The present invention provides a coloured soda-lime glass whichcomprises the principal glass-forming constituents and colouring agentscomprising:

-   -   iron in a quantity which, expressed in weight of the oxide Fe₂O₃        in relation to the total weight of glass, is greater than or        equal to 0.5, and less than or equal to 1.0% (quantity of total        iron),    -   ferrous iron in a quantity which, expressed in weight of atoms        of Fe²⁺ in relation to the total weight of iron atoms present in        the glass, lies in the range of between 20 and 65% (ratio of        Fe²⁺/total Fe),    -   titanium in a quantity which, expressed in weight of TiO₂ in        relation to the total weight of glass, is greater than or equal        to 1.0%, and the glass has:    -   a light transmission, measured for illuminant A and calculated        for a thickness of 4 mm (TLA4), which lies in the range of        between 15 and 55%,    -   a total transmission in the ultraviolet measured for a thickness        of 4 mm (TUV4) of less than or equal to 30%,    -   a dominant wavelength in transmission (λ_(D)) of less than or        equal to 491 nm.

It has been found that such a glass allows commercially desirableconsiderations relating to both aesthetics and energy to be met. In theautomotive sector in particular a coloured glass according to theinvention can have a blue tint, with a wavelength in transmission ofless than or equal to 491 nm, which is appreciated by motor vehiclemanufacturers, a low light transmission and a low total transmission inthe ultraviolet enabling the unpleasing discolouration of the objectslocated inside areas enclosed by this glass to be restricted.

The presence of titanium in a quantity which, expressed in weight ofTiO₂ in relation to the total weight of glass is greater than or equalto 1.0%, combined with the composition criteria relating to iron, allowsa glass to be produced with a wavelength in transmission, lighttransmission and total transmission in the ultraviolet that meet presentcriteria relating to aesthetics and energy, especially required by motorvehicle manufacturers.

Iron is present in the majority of glasses currently on the market, inparticular in coloured glasses. The presence of Pe³⁺ provides the glasswith a light absorption of the visible light of short wavelength (410and 440 nm) and a very high absorption band in the ultraviolet(absorption band centred at 380 nm), while the presence of Fe²⁺ ionscauses a high absorption in the infrared (absorption band centred at1050 nm). The presence of Fe³⁺ gives the glass a slight yellowcoloration, generally regarded as not very pleasing, while ferrous,Fe²⁺, ions give a pronounced blue-green coloration. A strongconcentration of Fe²⁺ in the glass therefore allows the energytransmission TE to be reduced and a pleasing coloration to be provided.However, the presence of iron in the bath of molten glass results in anabsorption of infrared radiation which can hinder heat diffusion in theglass production furnace, and therefore make this production moredifficult. Moreover, when the concentration of iron increases, the lighttransmission of the glass decreases.

The energy and optical properties of a glass, in particular its colour,its light transmission and its total transmission in the ultraviolet,result from a complex interaction between its components. The behaviourof components of the glass depends on their redox state and therefore onthe presence of other components which can influence this redox state.

It has been found that the glass as defined in the claims enablesaesthetic criteria (colour) and optical/energy criteria (lighttransmission and total transmission in the ultraviolet) to be respondedto by easily controlling its composition, particularly in terms of ironand titanium.

Preferably, the quantity of total iron is less than or equal to 0.90%,and preferably less than or equal to 0.89%. This facilitates thetransition of the production of clear glass to the production ofcoloured glass.

Preferably, the quantity of total iron is at least 0.7% or even at least0.75%. This promotes not only the formation of a colour that is pleasingto the eye, but also the formation of a low light transmission as wellas a low energy transmission.

Preferably, the glass according to the invention comprises ferrous ironin a quantity which, expressed in weight of atoms of Fe²⁺ in relation tothe total weight of iron atoms present in the glass, lies in the rangeof between 20 and 65%, preferably between 35 and 55%, and advantageouslybetween 40 and 50%. Such a ratio enables a glass to be obtained thatcombines a good selectivity with a low transmission in the ultraviolet.

Preferably, the glass according to the invention comprises titanium in aquantity which, expressed in weight of TiO₂ in relation to the totalweight of glass, is greater than 1.1%, preferably greater than 1.3%, inorder to restrict as far as possible the unpleasing discoloration ofobjects located inside areas enclosed by the glass according to theinvention under the effect of ultraviolet solar radiation.

To produce a glass with a colour which is commercially desirable as itis considered to be pleasing to the eye, the glass according to theinvention can contain one or more of the following colouring agents inaddition to those already mentioned.

Cobalt

The presence of cobalt tends to give the glass an intense blue colour.Preferably, the glass according to the invention comprises cobalt in aquantity which, expressed in weight of Co in relation to the totalweight of glass, is greater than 75 ppm, and even greater than 100 ppm.Preferably, the quantity of cobalt is less than or equal to 350 ppm, andadvantageously less than or equal to 250 ppm. A quantity of cobalt thatis too high can in fact impair the selectivity of the glass.

In a preferred form, the glass according to the invention comprises theprincipal glass-forming constituents and colouring agents, the colouringagents consisting essentially of Fe, Ti and Co according to at least oneof the ranges mentioned above.

In another preferred form, the glass according to the inventioncomprises the principal glass-forming constituents and colouring agents,the colouring agents consisting of Fe, Ti and Co according to at leastone of the ranges mentioned above.

Chromium

The presence of Cr^(III) tends to give the glass a light greencoloration, whereas the presence of Cr^(VI) produces a very intenseabsorption band of 365 nm and a yellow coloration of the glass.Preferably, the glass comprises chromium in a quantity which, expressedin weight of Cr₂O₃ in relation to the total weight of glass, is at least5 parts per million (ppm). In some cases, the glass can comprisechromium in a quantity that is greater than or equal to 50 ppm, and evengreater than or equal to 100 ppm. Preferably the quantity of chromium isless than 1000 ppm, and advantageously less than or equal to 500 ppm.

In a preferred form, the glass according to the invention comprises theprincipal glass-forming constituents and colouring agents, the colouringagents consisting essentially of Fe, Ti, Co and Cr according to at leastone of the ranges mentioned above.

In another preferred form, the glass according to the inventioncomprises the principal glass-forming constituents and colouring agents,the colouring agents consisting of Fe, Ti, Co and Cr according to atleast one of the ranges mentioned above.

Vanadium

The presence of vanadium tends to give the glass a green tint.Preferably, the glass according to the invention comprises vanadium in aquantity which, expressed in weight of V₂O₅ in relation to the totalweight of glass, is less than 1000 ppm, and advantageously less than 500ppm.

The light transmission TLA4 of the coloured glass according to theinvention lies in the range of between 15 and 55%, preferably between 20and 45%, and advantageously between 25 and 35%. This makes this glasswell suited for use, for example, as glazing for motor vehicles, inparticular for side glazing, rear-view windows, roof glazing or alsoopening roofs.

The total transmission in the ultraviolet (TV4) of the coloured glassaccording to the invention is preferably less than or equal to 30%, butcan be less than or equal to 25%, and advantageously less than or equalto 20%. Such values for TUV4 help to prevent the unpleasingdiscoloration of objects located in areas enclosed by such a glass andexposed to ultraviolet solar radiation.

It is desirable if the coloured glass according to the invention has anenergy transmission TE4 of less than 45%, preferably less than 35%, andadvantageously less than 25%. A low energy transmission helps limit thetemperature increase in the internal area enclosed by the glassaccording to the invention, such as a building or motor vehicle, duringexposure to the sun.

The glass according to the invention preferably has a selectivitygreater than 1.0, preferably greater than 1.1. A high selectivity isadvantageous both for applications in motor vehicles and inarchitectural applications, since it helps limit the temperatureincrease associated with solar radiation, and thus increase the thermalcomfort of occupants of the vehicle or building while providing highnatural illumination and visibility through the glazing.

With respect to the colour of the glass according to the invention, itis desirable if its dominant wavelength in transmission λ_(D) is lessthan or equal to 489 nm. This corresponds to a glass whose colour intransmission is generally tinted blue, which is pleasing to the humaneye and is highly appreciated commercially, in particular for glazingfor motor vehicles. It is advantageous if the glass has a λ_(D) of lessthan or equal to 487 nm.

The excitation purity in transmission of the glass according to theinvention is preferably greater than 10%, and preferably greater than15%. This corresponds to a pronounced tint, which is commerciallydesirable. In some cases, the excitation purity in transmission can begreater than or equal to 20%, and even greater than 25%.

It is desirable if the glass according to the invention comprises lessthan 0.5% of cerium, expressed in weight of CeO₂ in relation to thetotal weight of glass. Advantageously, the glass according to theinvention comprises less than 0.3% of CeO₂, preferably less than 0.1%.Cerium has a tendency to cause the dominant wavelength to shift towardsgreen and yellow, which is contrary to the preferred tint. Moreover,cerium is a very costly component.

According to a preferred embodiment, the glass according to theinvention comprises the principal glass-forming constituents andcolouring agents, the colouring agents consisting essentially of Fe, Ti,Co, Cr and Ce.

In another preferred embodiment, the glass according to the inventioncomprises the principal glass-forming constituents and colouring agents,the colouring agents consisting of Fe, Ti, Co, Cr and Ce.

The glass according to the invention preferably comprises less than 200parts per million (ppm), preferably less than 100 ppm, of nickel,expressed in weight of NiO in relation to the total weight of glass. Thepresence of nickel can impair the selectivity of the glass containingit, since it does not absorb light in the infrared range, which resultsin a significant energy transmission value. In addition, it gives theglass a yellow coloration. Moreover, the presence of nickel can causedifficulties in the production of glass (formation of sulphides,inclusions of nickel in the glass). In particular embodiments, the glassaccording to the invention is free of nickel as colouring agent.

Advantageously, the glass according to the invention comprises less than1500 parts per million, preferably less than 500 parts per million, ofmanganese expressed in weight of MnO₂ in relation to the total weight ofglass. Manganese in the form of MnO₂ has an oxidising character whichcan modify the redox state of the iron and induce a green hue.

Preferably, the glass according to the invention comprises more than 2%by weight of magnesium oxide MgO in relation to the total weight ofglass. The presence of magnesium benefits the fusion of the constituentsduring melting of the glass.

Advantageously, the glass according to the invention comprises less than30 parts per million of selenium, preferably less than 20 parts permillion by weight of Se in relation to the total weight of glass. Thepresence of selenium as colouring agent can promote a low lighttransmission, but if present in too large a quantity, it can give theglass an unwanted pink or red coloration.

According to a preferred form of the invention, the colouring agents arepresent in a quantity corresponding to the following proportions(expressed as a percentage of the total weight of glass in the formindicated): Fe₂O₃ 0.7-0.9% TiO₂ 1.0-2.0% Co 140-240 ppm Cr₂O₃  0-400 ppmSe   0-10 ppm

According to a preferred embodiment, the glass according to theinvention comprises the principal glass-forming constituents andcolouring agents, the colouring agents consisting essentially of Fe, Ti,Co, Cr and Se according to at least one of the ranges mentioned above.

In another preferred embodiment, the glass according to the inventioncomprises the principal glass-forming constituents and colouring agents,the colouring agents consisting of Fe, Ti, Co, Cr and Se according to atleast one of the ranges mentioned above.

It is desirable if this glass does not contain fluorinated compounds, orat least if these do not constitute more than 0.2% by weight of F inrelation to the glass. These compounds in fact generate furnacedischarges which are harmful to the environment and are, moreover,corrosive with respect to the refractory materials which line the insideof the production furnace.

The coloured glass according to the invention preferably forms a glazingfor motor vehicles. It may, for example, be advantageously used for sideglazing or rear-view windows of a vehicle or roof glazing or openingroofs.

The glass according to the invention may be coated with a layer. Forexample, this can be a layer of metal oxides, which reduce thetemperature increase resulting from solar radiation and consequently thetemperature increase inside the passenger compartment of a vehicle usingsuch glass as glazing.

The glasses according to the invention can be manufactured byconventional processes. As batch materials, it is possible to usenatural materials, recycled glass, slag or a combination of thesematerials. The colouring agents are not necessarily added in the formindicated, but this manner of giving the amounts of colouring agentsadded in equivalents in the forms indicated corresponds to standardpractice. In practice, iron is added in the form of red iron oxide,cobalt is added in the form of hydrated sulphate, such as CoSO₄.7H₂O orCoSO₄.6H₂O and chromium is added in the form of dichromate such asK₂Cr₂O₇. Cerium is often introduced in oxide or carbonate form, titaniumin oxide form, and vanadium in the form of vanadium oxide or sodiumvanadate. Selenium, when present, can be added in elemental form or inselenite form such as Na₂SeO₃ or ZnSeO₃.

Other elements are sometimes present as a result of impurities in thebatch materials used to manufacture the glass according to theinvention, whether these are natural materials, recycled glass or slag,which are increasingly used, but when these impurities do not give theglass properties outside the limits defined above, these glasses areregarded as complying with the present invention.

The present invention shall now be illustrated by the followingexamples:

EXAMPLES 1 to 68

Table I specifies by way of non-restrictive indication the basecomposition of the glass. It should be understood that a glass with thesame optical and energy properties can be obtained with a basecomposition having amounts of oxides lying within the ranges ofpercentages by weight given at the beginning of the present description.

The glasses according to the examples comprises less than 100 parts permillion (ppm) of NiO, less than 500 ppm of MnO₂ and, unless specifiedotherwise, less than 3 ppm of Se, less than 0.1% of CeO₂ and more than2% of MgO. TABLE I Analysis of the base glass SiO₂ 71.5-71.9% Al₂O₃ 0.8% CaO  8.8% MgO  4.2% Na₂O 14.1% K₂O  0.1% SO₃ 0.05-0.45%

The following table gives the concentrations of the components, theoptical and energy properties of glasses according to the invention. Theconcentrations are determined by X-ray fluorescence of the glass and areconverted into the indicated molecular state. TABLE II Fe²⁺/ Fe₂O₃ Fetot TiO₂ Co Cr₂O₃ Se CeO₂ TLA4 TUV4 TE4 P Ex. (%) (%) (%) (ppm) (%)(ppm) (%) (%) (%) λ_(D)(nm) (%) (%) SE 1 0.850 40.00 1.0 140 200 37.415.6 490.2 25.4 18.0 1.47 2 0.850 45.00 1.5 180 100 31.7 13.9 489.2 20.821.2 1.52 3 0.875 42.00 1.3 180 200 23.1 14.1 489.3 21.8 21.6 1.47 40.875 42.00 1.8 200 20 30.7 12.2 489.4 21.5 20.6 1.43 5 0.875 42.00 2.0240 100 26.1 11.7 488.9 19.5 23.9 1.33 6 0.875 55.00 2.1 270 350 16.112.0 489.5 8.6 29.5 1.88 7 0.875 42.00 1.2 300 340 20.5 14.7 484.1 17.542.2 1.17 8 0.700 40.00 1.0 345 450 39.9 19.1 489.3 29.3 18.1 1.36 90.700 45.00 1.5 180 100 34.1 17.4 488.4 24.7 21.3 1.38 10 0.650 42.001.3 180 200 35.7 19.4 488.1 27.7 21.8 1.29 11 0.520 42.00 1.8 200 2036.4 20.5 487.4 30.8 20.8 1.18 12 0.600 42.00 2.0 240 100 30.5 18.2487.6 26.8 24.1 1.14 13 0.590 55.00 2.1 270 350 20.7 18.7 488.5 16.129.7 1.29 14 0.950 42.00 1.2 300 340 19.3 12.9 484.4 15.6 42.1 1.24 150.700 55.00 1.0 100 100 38.3 18.9 489.9 21.3 17.7 1.80 16 0.850 40.001.0 140 100 38.2 15.4 488.6 26.0 19.1 1.47 17 0.850 40.00 1.0 180 0 35.515.2 484.5 25.4 27.3 1.40 18 0.875 45.00 1.3 190 0 31.6 13.7 485.8 20.726.7 1.53 19 0.870 45.00 1.8 260 0 24.4 12.2 485.2 18.0 32.2 1.36 200.875 42.00 2.0 300 100 20.7 11.7 485.6 17.8 34.3 1.17 21 0.850 40.002.1 330 0 19.8 11.8 483.9 19.2 38.8 1.03 22 0.875 42.00 1.5 330 500 15.914.1 485.6 15.3 41.4 1.04 23 0.950 40.00 1.1 190 50 32.4 12.6 485.7 22.026.9 1.47 24 0.975 42.00 1.2 210 100 28.8 11.8 485.9 19.0 29.2 1.52 251.000 40.00 1.0 220 110 28.6 11.9 484.6 19.6 32.8 1.46 26 0.925 45.001.5 280 230 20.5 12.4 485.3 15.1 37.0 1.36 27 0.650 42.00 1.1 330 95016.9 21.7 486.8 19.2 41.7 0.88 28 0.700 42.00 1.0 100 0 44.2 18.7 489.830.4 14.2 1.46 29 0.600 65.00 2.0 240 100 21.5 18.2 486.5 11.7 32.3 1.8330 0.800 59.00 2.1 250 120 19.3 13.3 487.8 9.8 30.2 1.96 31 0.900 40.001.0 140 0 0.1 31.9 9.0 482.3 23.9 28.0 1.33 32 0.850 45.00 1.3 210 10029.4 14.5 485.8 20.2 29.0 1.46 33 0.890 42.00 1.4 220 60 29.2 13.1 485.720.9 28.8 1.40 34 0.700 44.00 1.35 200 100 33.0 17.8 486.0 25.0 26.41.32 35 0.880 40.00 1.4 220 0 30.6 13.2 485.0 22.8 28.8 1.34 36 0.89042.00 2.0 300 30 21.0 11.2 485.0 17.8 35.1 1.18 37 0.850 38.00 2.0 300200 21.9 12.5 486.6 20.4 31.7 1.07 38 0.550 32.00 1.0 120 40 48.5 22.3488.3 40.0 13.8 1.21 39 0.847 43.34 1.1 139 341 28.8 11.9 487.0 21.023.7 1.37 40 0.850 44.00 1.3 150 100 10 25.8 10.7 485.8 19.6 19.3 1.3241 0.900 36.00 1.2 150 50 14 27.8 9.7 485.5 23.4 15.5 1.19 42 0.85039.00 1.3 160 0 15 25.6 10.6 484.1 22.1 17.1 1.16 43 1.000 42.00 1.0 190500 6 15.5 9.3 486.2 13.0 27.7 1.19 44 1.000 50.00 1.0 162 30 30 15.68.1 485.0 9.1 14.6 1.71 45 0.850 45.00 1.0 145 100 20 24.7 11.6 485.418.4 15.9 1.34 46 0.900 55.00 1.4 150 0 20 19.0 9.1 486.8 10.2 16.1 1.8747 0.890 40.00 1.05 200 220 8 17.9 11.2 482.3 17.9 30.5 1.00 48 0.88036.00 2.0 215 35 11 15.8 8.2 485.4 19.1 19.0 0.83 49 0.900 40.00 1.0 1400 28 25.7 10.2 486.9 20.1 8.8 1.27 50 0.847 43.34 1.1 139 250 0.4 29.26.8 486.3 21.9 23.8 1.33 51 0.850 44.00 1.3 150 100 0.1 27.9 9.5 484.521.0 25.9 1.33 52 0.900 36.00 1.2 150 50 0.1 30.9 8.5 483.6 25.3 25.01.22 53 0.850 39.00 1.5 160 0 0.1 28.6 9.4 483.8 23.8 24.6 1.20 54 1.00042.00 1.0 190 500 0.2 16.6 6.9 485.7 14.0 31.4 1.19 55 1.000 50.00 1.0162 30 0.2 22.2 6.3 482.2 13.2 35.1 1.68 56 0.850 45.00 1.0 145 100 0.428.8 6.8 483.3 21.3 28.8 1.35 57 0.900 55.00 1.4 120 0 0.1 28.7 7.6485.9 14.8 24.1 1.94 58 0.890 40.00 1.05 120 100 0.1 34.7 9.1 485.3 24.822.2 1.40 59 0.880 36.00 2.0 215 35 0.2 18.1 5.8 484.2 20.7 26.1 1.33 600.550 24.00 1.0 80 140 54.4 22.5 490.2 45.9 18.0 1.19 61 0.650 26.00 1.540 100 54.8 18.5 489.2 42.6 21.2 1.29 62 0.700 30.00 1.3 180 200 39.618.2 489.3 34.2 21.6 1.16 63 0.810 31.00 1.8 160 60 39.3 13.7 489.4 31.420.6 1.25 64 0.770 32.00 2.0 240 100 31.7 14.2 488.9 28.8 23.9 1.10 650.500 20.00 1.0 200 400 44.0 24.2 489.5 44.7 29.5 0.98 66 0.550 35.001.2 300 340 28.5 22.3 484.1 30.7 42.2 0.93 67 0.650 40.00 1.0 330 45021.8 20.9 483.3 23.5 53.6 0.93 68 0.700 28.00 1.0 40 100 54.3 18.9 483.640.8 53.5 1.33

1-41. (canceled)
 42. Coloured soda-lime glass which comprises principalglass-forming constituents and colouring agents: total iron in aquantity which, expressed in weight of the oxide Fe₂O₃ in relation tothe total weight of glass, is greater than or equal to 0.5% and lessthan or equal to 1.0%; ferrous iron in a quantity which, expressed inweight of atoms of Fe²⁺ in relation to total weight of iron atomspresent in the glass (ratio of Fe²⁺/total Fe), lies in the range ofbetween 20% and 65%; titanium in a quantity which, expressed in weightof TiO₂ in relation to the total weight of glass, is greater than orequal to 1.0%; and the glass has: a light transmission, measured forilluminant A and calculated for a thickness of 4 mm (TLA4), which liesin the range of between 15% and 55%; a total transmission in theultraviolet measured for a thickness of 4 mm (TUV4) of less than orequal to 30%; and a dominant wavelength in transmission (λ_(D)) of lessthan or equal to 491 nm.
 43. Coloured soda-lime glass according to claim42, characterised by at least one of the following (A) through (H): (A)the quantity of total iron is further defined as being: (i) less than orequal to 0.90%; (ii) less than or equal to 0.89%; (iii) at least 0.70%;(iv) at least 0.75%; (v) (i) and (iii); or (vi) (ii) and (iv); (B) thequantity of titanium is further defined as being: (i) greater than 1.1%;or (ii) greater than 1.3%; (C) cobalt is present as a colouring agent ina quantity which, expressed in weight of Co in relation to the totalweight of glass, is: (i) greater than 75 ppm; (ii) greater than 100 ppm;(iii) less than or equal to 350 ppm; (iv) less than or equal to 250 ppm;(v) (i) and (iv); or (vi) (ii) and (iii); (D) chromium is present as acolouring agent in a quantity which, expressed in weight of Cr₂O₃ inrelation to the total weight of glass is: (i) at least 5 ppm; (ii) atleast 50 ppm; (iii) at least 100 ppm; (iv) less than 1000 ppm; (v) lessthan 500 ppm; (vi) less than or equal to 500 ppm; or (vii) (iii) and(vi); (E) the quantity of Fe²⁺ is further defined being: (i) within therange of between 35% and 55%; or (ii) within the range of between 40%and 50%; (F) TLA4 is further defined as being: (i) within the range ofbetween 20% and 45%; or (ii) within the range of between 25% and 35%;(G) TUV4 is further defined as being: (i) less than or equal to 25%; or(ii) less than or equal to 20%; (H) λ_(D) is further defined as being:(i) less than or equal to 489 nm, or (ii) less than or equal to 487 nm.44. Coloured soda-lime glass according to claim 43, furthercharacterised by at least two of the aforementioned features (A) through(H).
 45. Coloured soda-lime glass according to claim 43, furthercharacterised by at least three of the aforementioned features (A)through (H).
 46. Coloured soda-lime glass according to claim 43, furthercharacterised by at least four of the aforementioned features (A)through (H).
 47. Coloured soda-lime glass according to claim 43, furthercharacterised by all of the aforementioned features (A) through (H). 48.Coloured soda-lime glass according to claim 43, characterised by atleast one of the following (I) through (M): (I) vanadium is present as acolouring agent in a quantity which, expressed in weight of V₂O₅ inrelation to the total weight of glass, is: (i) less than 1000 ppm; or(ii) less than 500 ppm; (J) selenium is present as a colouring agent ina quantity which, expressed in weight of Se in relation to the totalweight of glass, is: (i) less than 30 ppm; or (ii) less than 20 ppm; (K)the glass has an energy transmission measured according to the Moondistribution and calculated for a thickness of 4 mm (TE4) of: (i) lessthan 45%; (ii) less than 35%; or (iii) less than 25%; (L) the glass hasa selectivity (SE4) which is: (i) greater than 1.0; or (ii) greater than1.1; (M) the glass has an excitation purity in transmission which is:(i) greater than 10% or (ii) greater than 15%.
 49. Coloured soda-limeglass according to claim 43, further characterised by at least two ofthe aforementioned features (I) through (M).
 50. Coloured soda-limeglass according to claim 43, further characterised by at least three ofthe aforementioned features (I) through (M).
 51. Coloured soda-limeglass according to claim 43, further characterised by all of theaforementioned features (I) through (M).
 52. Coloured soda-lime glassaccording to claim 42, characterised by at least one of the following(I) through (M): (I) vanadium is present as a colouring agent in aquantity which, expressed in weight of V₂O₅ in relation to the totalweight of glass, is: (i) less than 1000 ppm; or (ii) less than 500 ppm;(J) selenium is present as a colouring agent in a quantity which,expressed in weight of Se in relation to the total weight of glass, is:(i) less than 30 ppm; or (ii) less than 20 ppm; (K) the glass has anenergy transmission measured according to the Moon distribution andcalculated for a thickness of 4 mm (TE4) of: (i) less than 45%; (ii)less than 35%; or (iii) less than 25%; (L) the glass has a selectivity(SE4) which is: (i) greater than 1.0; or (ii) greater than 1.1; (M) theglass has an excitation purity in transmission which is: (i) greaterthan 10% or (ii) greater than 15%.
 53. Coloured soda-lime glassaccording to claim 52, further characterised by at least two of theaforementioned features (I) through (M).
 54. Coloured soda-lime glassaccording to claim 52, further characterised by at least three of theaforementioned features (I) through (M).
 55. Coloured soda-lime glassaccording to claim 52, further characterised by all of theaforementioned features (I) through (M).
 56. Coloured soda-lime glassaccording to claim 43, further characterised in that the colouringagents consist essentially of iron, titanium and cobalt.
 57. Colouredsoda-lime glass according to claim 43, further characterised in that thecolouring agents consist of iron, titanium and cobalt.
 58. Colouredsoda-lime glass according to claim 43, further characterised in that thecolouring agents consist essentially of iron, titanium, cobalt andchromium.
 59. Coloured soda-lime glass according to claim 43, furthercharacterised in that the colouring agents consist of iron, titanium,cobalt and chromium.
 60. Coloured soda-lime glass according to claim 42,characterised in that it comprises nickel in a quantity which, expressedin weight of NiO in relation to the total weight of glass, is: (i) lessthan 200 parts per million; or (ii) less than 100 parts per million. 61.Coloured soda-lime glass according to claim 42, characterised in thatthe colouring agent further comprises cerium in a quantity which,expressed in weight of CeO₂ in relation to the total weight of glass,is: (i) less than 0.5%; (ii) less than 0.3%; or (iii) less than 0.1%.62. Coloured soda-lime glass according to claim 42, characterised inthat it is covered by a layer.